Each box of Cheerios (a breakfast cereal) contains a prize. There are 6 different prizes. On average, how many boxes of Cheerios do you need to buy to get all 6 different prizes? This web page is a colourful simulation of the problem.

http://www.mathwire.com/data/CerealApplet.html

This page generates a random integer. You can choose the range.
http://www.oswego.org/ocsd-web/games/RndGenerator/rndnogen.html

Here are a variety of probability experiments, from throwing coins, throwing dice, choosing playing cards and spinning spinners.

Throwing coins
http://www.random.org/coins/

Throwing dice
http://www.random.org/dice/

Drawing playing cards
http://www.random.org/playing-cards/

Spinning spinners
http://www.standards.dfes.gov.uk/primary/teachingresources/mathematics/n...

If you have 24 people in a room, what is the chance that at least two of them have the same birthday? What about 30 people? 50 people? This applet simulates the problem. The answer may surprise you!
http://www-stat.stanford.edu/~susan/surprise/Birthday.html

This probability game is an electronic version of the old TV game show Let's Make a Deal, hosted by Monty Hall. It has a surprising outcome!
http://nlvm.usu.edu/en/nav/frames_asid_117_g_3_t_2.html?open=instruction...

This is a flash-based flipchart that can be used as an introduction to probability. It is based on a casino game, so permission to use it should be sought from the Head of Department or the Principal.